using System;
using System.Collections.Generic;
using System.Text;
using System.IO;

namespace SysTables
{
    public class File
    {

        public static byte[] Read(string filename)
        {
            FileStream inputFile = new FileStream(filename, FileMode.Open);
            byte[] buff =  Read(inputFile, 0);
            inputFile.Close();
            return buff;
        }

        public static byte[] Read(Stream stream, int initialLength)
        {
            // If we've been passed an unhelpful initial length, just
            // use 32K.
            if (initialLength < 1)
            {
                initialLength = 32768;
            }

            byte[] buffer = new byte[initialLength];
            int read = 0;

            int chunk;
            while ((chunk = stream.Read(buffer, read, buffer.Length - read)) > 0)
            {
                read += chunk;

                // If we've reached the end of our buffer, check to see if there's
                // any more information
                if (read == buffer.Length)
                {
                    int nextByte = stream.ReadByte();

                    // End of stream? If so, we're done
                    if (nextByte == -1)
                    {
                        return buffer;
                    }

                    // Nope. Resize the buffer, put in the byte we've just
                    // read, and continue
                    byte[] newBuffer = new byte[buffer.Length * 2];
                    Array.Copy(buffer, newBuffer, buffer.Length);
                    newBuffer[read] = (byte)nextByte;
                    buffer = newBuffer;
                    read++;
                }
            }
            // Buffer is now too big. Shrink it.
            byte[] ret = new byte[read];
            Array.Copy(buffer, ret, read);
            return ret;
        }

        public static bool Save(string filename,byte[] buffer)
        {
            FileStream outputFile = new FileStream(filename, FileMode.Create);
            outputFile.Write(buffer, 0, buffer.Length);
            outputFile.Close();
            return true;
        }

    }
}
